Physics Based Requirements for Qualification of BGA Components in Temperature Cycling

2015 ◽  
Author(s):  
Ru Han ◽  
Milena Vujosevic ◽  
Min Pei
Keyword(s):  
Deformation Process ◽  
Temperature Cycling ◽  
New Approach ◽  
Deformation And Failure ◽  
Joint Reliability ◽  
Rapid Changes ◽  
Temperature Cycling Test ◽  
Definition Of ◽  
The Impact ◽  
Package Materials

This paper discusses a new approach for definition of temperature cycling qualification requirement that accounts for the physics of the deformation process in use condition and in the accelerated temperature cycling test condition. The methodology is used to define solder joint reliability (SJR) requirement for Package on Package (PoP) components. Included in the study is the impact of adhesives on SJR requirements. The approach used is different from standards-based approaches that define the requirements in the way that is often independent of package materials and geometries. Physics based damage metrics and numerical modeling was used to comprehend design, technology, material, and temperature profile and provide an in-depth understanding of package deformation and failure mechanism. This, coupled with a developed fatigue law was then used to translate use conditions to test condition requirement. The study shows that accelerated test will not accelerate all PoP solder joints equally and that requirements for PoP to board interconnects will be different from requirements for top–to–bottom package interconnects. Similarly, for component with adhesives, when requirements are based on physics, they must be different than requirements for component without adhesive and those requirement should be a function of adhesive thermo-mechanical material properties. Given rapid changes in technology, explosion of new devices and new use conditions, manufacturers constantly make tradeoffs between performance, cost and reliability. The qualification process needs to be optimized to meet these increasing challenges and qualification based on knowledge of physics presented in this paper is designed to meet these challenges.

Fabrication and Reliability Assessment of Cu Pillar Micro-bumps with Printed Polymer Cores

2020 ◽  
Author(s):  
Xing QIU ◽  
Jeffery Lo ◽  
Yuanjie CHENG ◽  
Shi-Wei Ricky Lee ◽  
Yong Jhe TSENG ◽  
...  
Keyword(s):  
Flip Chip ◽  
Reliability Assessment ◽  
Temperature Cycling ◽  
Thermomechanical Stress ◽  
Joint Reliability ◽  
Cu Pillar ◽  
Bonding Technology ◽  
Temperature Cycling Test ◽  
Reliability Performance ◽  
Cycling Condition

Abstract Cu pillar micro-bumps with polymer cores have been demonstrated to effectively reduce thermomechanical stress and improve joint reliability. Fabricating polymer cores by a printing approach was proposed to overcome the limitations in conventional fabrication process. Cylindrical polymer cores with diameter of 20 µm and height of 30 µm were successfully printed. Surface metallization was subsequently applied on the printed polymer cores and Cu pillar micro-bumps with printed polymer cores with diameter of 35 µm and height of 35 µm were eventually achieved. To study the reliability performance of the interconnect joints made of Cu pillar micro-bumps with printed polymer cores, flip-chip bonding technology was successfully introduced and the interconnect joints between a designed BT substrate and a silicon chip were formed. The interconnect joints made of conventional Cu pillars with identical dimensions were prepared for comparison. The reliability performance of the joints was investigated under temperature cycling condition and drop condition, respectively. Printed polymer cores increased the characteristic life by 32% in a temperature cycling test (0°C-100°C), while the drop test showed that printed polymer cores increased the characteristic life by 4 times due to the extra compliance provided by the printed polymer cores. It can be concluded that Cu pillar micro-bumps with printed polymer cores can effectively reduce stress and improve joint reliability.

scholarly journals Methodology for Defining the Digital Economy

2019 ◽  
Vol 13 (4) ◽  
pp. 79-89 ◽  
Author(s):  
Yu. V. Belousov ◽  
O. I. Timofeeva
Keyword(s):  
Economic Activity ◽  
Policy Development ◽  
Digital Economy ◽  
Management Systems ◽  
Theoretical Studies ◽  
New Approach ◽  
Production Processes ◽  
Sectoral Approach ◽  
Definition Of ◽  
The Impact

The digital economy is a new, quite fast developing, social and economic phenomenon. The economic theory lags significantly behind the dynamics of this phenomenon. Until now, the term digital economy has been understood by analytical and empirical specialists as various phenomena and processes. In this article, we propose a new approach to defining the essence of the digital economy. Thus, we analyse available definitions of the term digital economy based mainly on the sectoral approach. Here arise problematic issues when using this approach to the definition of the digital economy. Besides, we make a distinction between the terms the digital economy and the digital sector of economy, as well as a criterion to distinguish the digital and non-digital economy. We pay much attention to new approaches to defining the digital economy. Some researchers based the research and the definition, taking into account the impact of a man as an operator of production processes acting on objects and instruments. On the contrary, in this article we define the digital economy as an economic activity of people focusing on a feature that the impact of a person as a manufacturer of products is not on objects of labour and instruments but management systems of such instruments. So, the non-digital economy is characterised by the impact of a person on objects or instruments. Firstly, the digital sector of the economy is production where a person influences the systems of instrument management. Secondly, the development and design of new systems of instrument management. Results of theoretical studies of the essence of the digital economy have essential applications. First of all, it concerns the issues of state policy development in the digital economy.

scholarly journals Interim Management as a New Approach to the Company Management

2020 ◽  
Vol 8 (1) ◽  
pp. 20-26
Author(s):  
H. Dźwigoł
Keyword(s):  
Business Environment ◽  
Modern Approach ◽  
New Approach ◽  
Rapid Changes ◽  
The Future ◽  
Interim Management ◽  
The Impact

The article presented the importance of employing interim managers in the conditions of rapid changes in the business environment. The significance of interim management as a modern approach to management was highlighted. The author also pondered on how the companies of the future should be managed. Furthermore, the author presented his own experiences and findings acquired from projects he had carried out as an interim manager. The readers’ attention was drawn to the impact of the interim management on the organisational entrepreneurship.

How international law impacts on statelessness and citizenship: the case of Kurdish nationalism, conflict and peace

2016 ◽  
Vol 12 (1) ◽  
pp. 42-62 ◽  
Author(s):  
Latif Tas
Keyword(s):  
International Law ◽  
Country Of Origin ◽  
Ethnic Community ◽  
New Approach ◽  
International Laws ◽  
Definition Of ◽  
The Impact ◽  
The Relationship ◽  
Stateless Person

AbstractThis paper argues for a new approach to understanding statelessness. It explores the limits of international laws on statelessness and the relationships between statelessness, diaspora and nationalism. It discusses how the condition of statelessness has affected Kurds, and how statelessness has been constructed and experienced at an individual and collective level in the diaspora. It argues for an expanded definition of the international laws of ‘stateless’ person: adding to the accepted de jure and highly contested de facto definitions, by also suggesting a third, new, category of ‘socially stateless’ people. The paper examines the concept of diaspora itself from the perspective of Kurdish interviewees and explores how, for stateless groups like Kurds, ‘living in diaspora’ can mean more than one place, including their land of origin. It will suggest the concept of ‘double’ or ‘multiple’ diasporas, where stateless people do not feel that they belong either to their country of origin or to the country in which they now live. The paper discusses the idea that when an ethnic community is stateless, then even those individuals who have an official nationality, citizenship or passport may often describe themselves as stateless. The relationship between statelessness, diaspora and nationalism is highlighted; and the impact of this on diaspora involvement in homeland politics, conflict and peace is explored. The paper also argues that the lack of protection which international law(s) offer around statelessness paradoxically create new forms of nationalism.

Equity & Trusts

2019 ◽  
Author(s):  
Paul S. Davies ◽  
Graham Virgo
Keyword(s):  
Private Law ◽  
Privy Council ◽  
New Approach ◽  
The Subject ◽  
The Common ◽  
Limitation Periods ◽  
The Law ◽  
Definition Of ◽  
The Impact ◽  
Academic Debate

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. Equity & Trusts: Text, Cases, and Materials provides a guide to the subject by providing analyses of the law of equity and trusts with extracts from cases and materials. This book provides analysis of significant recent key cases including the Supreme Court’s decision in Patel v Mirza where a new approach to determining the impact of the taint of illegality on private law claims was identified, which is of particular significance to claims for breach of trust and the recognition of the resulting trust. Other relevant decisions include: Angove’s Pty Ltd v Bailey, on the recognition of the constructive trust; Akers v Samba Financial Corp, on the nature of proprietary interests and rights under trusts; Ivey v Genting Casinos UK Ltd (t/a Crockfords Club), on the definition of dishonesty; and Burnden Holdings (UK) Ltd v Fielding, on limitation periods. Similarly, the Privy Council has heard important appeals in the area of Equity and trusts: notably Investec Trust (Guernsey) Ltd v Glenala Properties, on trustees and breach of trust and Marr v Collie, on the recognition of the common intention constructive trust. The impact of these developments has meant that there has been particularly significant rewriting of chapter 7 (constructive trusts) and chapter 9 (informal arrangements relating to land), plus significant rewriting of sections in other chapters, especially as to the nature of the rights and interests under a trust and the effect of illegality. The book is made up of nine parts that consider express private trusts, purpose trusts, non-express trusts, beneficiaries, trusties, variation, breach, and orders.

A Model for the Energy Absorption Capability of Composite Laminates

2006 ◽  
Author(s):  
Stefano Mian ◽  
Marino Quaresimin
Keyword(s):  
Composite Laminates ◽  
Master Curve ◽  
Material System ◽  
New Approach ◽  
External Data ◽  
Reinforcing Fibers ◽  
Laminate Thickness ◽  
Definition Of ◽  
Impact Data ◽  
The Impact

A new methodology for the analysis of impact data has been recently proposed [1], based on the definition of two normalised coefficients, the absorption coefficient (ratio of absorbed to penetration energy) and the intensity coefficient (ratio of impact to penetration energy). The new approach allowed the definition of an empirical master curve suitable to summarize the impact data irrespectively of material system, laminate thickness and lay-up. This work is oriented to quantitatively validate the master curve on the basis of experimental impact data previously obtained and other “external” data taken from the open literature, referred to laminates with significant variation of properties in terms of type and architecture of the reinforcing fibers, lay-up and thickness. In spite of the very large number of data collected for the validation, the master curve turned out suitable to describe all the normalized data with a reasonably reduced scatter.

scholarly journals About the equivalent level of flight safety

2020 ◽  
Vol 23 (5) ◽  
pp. 8-18
Author(s):  
B. I. Bachkalo ◽  
V. I. Zolotykh
Keyword(s):  
The State ◽  
Point Of View ◽  
Flight Safety ◽  
Minimal Set ◽  
Safety Level ◽  
Safety Measures ◽  
New Approach ◽  
Guidance Documents ◽  
Definition Of ◽  
The Impact

The article analyzes the meaning of the term "equivalent flight safety". The need for such an analysis is due to the fact that there is no definition of this term in the guidance documents on engineering and aerodrome flight support. This creates the ambiguous interpretation of the meaning embedded in this term and the possibility of non-compliance with the necessary flight safety measures at the aerodrome. As a result of the analysis, the expediency of the use of the term "equivalent level of flight safety" when determining the aerodrome operational suitability is substantiated. Management of the state of the aviation system from the point of view of information theory is considered. As a result, it was established that the ability to assess the impact of each element of the aviation system on its security against the effects of hazardous factors makes it possible to increase the efficiency of managing the state of this security. Dependence of the aerodrome flight safety level on the legality of the aerodrome operation is shown. The feasibility of achieving the equivalent level of flight safety using a new indicator, the equivalence coefficient, is substantiated. The formula that allows to calculate this indicator is derived. The numerical value of the equivalence coefficient depends on the values of the coefficients of compliance with the aerodromes operational suitability standards. The minimal set of evaluated elements is shown which determines the value of each coefficient of compliance with the aerodromes operational suitability standards. A mathematical model that reflects the dependence of the coefficient of compliance value with the operational suitability standards on the estimated indicators is constructed. The coefficients and indicators considered in the article in aggregate represent a new approach to assessing the level of aerodrome flight safety. This approach can be successfully applied in assessing the level of flight safety by any element of the aviation system.

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